can I embed a video in an email that will play within the email instead of linking to Vimeo or YouTube?

Phillip from Emma Support here! Regrettably, you would have to link to it just as you stated. The reason is that embedded videos make a mailing a little heavy for the recipient and some servers will block these types of files from coming through. This in turn would negatively affect your delivery rate, which we never want to happen. I wish that I had better news! If you have any additional questions on this, just let me know. Thanks!